BlackRock Inc. , the world’s biggest asset manager, named Rich Kushel as head of portfolio management and Charles Hallac as chief operating officer, reshaping its leadership team after the purchase of Barclays Global Investors.

BlackRock Inc., the world’s largest asset manager, hired Credit Suisse Group AG’s Andy Stewart to co-head the unit that runs real estate, hedge fund and private equity fund-of-funds investments along with Matthew Botein, according to a memo sent to employees.

BlackRock Inc., seeking to reverse withdrawals from active funds and boost assets as its acquisition spree ends, is expanding top leadership and shaking up its investment unit in the most sweeping overhaul since it became the world’s largest asset manager.